This article contains lists of tools and resources that Microsoft makes available to help you understand how to avoid or remove malware and viruses from your Windows-based computer.
You may experience any of the following symptoms on your computer:
You notice that the computer is unusually slow, crashes, or stops responding frequently.
You cannot start your virus scanner or some system tools, including Task Manager.
You cannot open certain webpages. In particular, you cannot open security-related webpages such as the Windows Update website.
You notice that your web browser's home page has changed unexpectedly, and you cannot restore the home page.
You receive constant and unexpected pop-up windows.
These symptoms may indicate that your computer is infected with malware. However, the same problems might also point to hardware or software issues that have nothing to do with malware. Because it is difficult to determine the reasons for your computer's strange behavior, we suggest that you review the information in this article to determine whether malware is causing the issue. Then, you can use the recommended tools and resources to remove the malware.
Microsoft security-related tools
Microsoft Windows Update
Run Windows Update to obtain the latest updates for Microsoft software, and this includes security updates that are released on the second Tuesday of each month. For more information, visit the Microsoft Update website:
Microsoft Security Essentials
Microsoft Security Essentials is free and can help protect your home or your small business system from viruses, spyware, and other malware. For more information, visit the following Microsoft webpage:
Microsoft Safety Scanner
If you think your computer is infected, we recommend that you run the Microsoft Safety Scanner. The scan is free and will detect and remove many of the issues that customers frequently contact us about. To run the Microsoft Safety Scanner, visit the following Microsoft webpage:
Microsoft Windows Defender Offline Beta
The Windows Defender Offline Beta can detect and remove malicious and potentially unwanted software, including rootkits. For more information, visit the following Microsoft webpage:
Microsoft Windows Security Center
Run the Windows Security Center to check the status of several security essentials on your computer. To do this, click Start, type Check security status, and then click Check security status. For more information about the Windows Security Center, visit the following Microsoft webpage:
The Windows firewall is included in most supported versions of Microsoft Windows. The Windows firewall can help protect your computer from malicious users. For more information, visit the following Microsoft webpages:
Microsoft security-related information centers
Microsoft Consumer Security Support Center
The Microsoft Consumer Security Support Center provides information about security products, fraud, issues with security Updates, and scanning, detecting, and removing threats:
Microsoft Malware Protection Center
The Malware Protection Center (MMPC) provides information about protection against viruses, spyware, and other potentially unwanted software. The MMPC also supplies the core anti-malware technology (This includes the scanning engine and the malware definition updates) for the following:
Forefront Server Security
Forefront Client Security
Microsoft Security Essentials
Windows Safety Scanner
Microsoft DaRTWindows Defender
Malicious Software Removal Tool.
For more information, visit the following Microsoft webpage:
Microsoft Malware Protection Center Encyclopedia
To learn more about the current top threats, visit the following Microsoft webpage:
Microsoft Virus and Security Solution Center
The Microsoft Virus and Security Solution Center provides free tools that can help detect and remove viruses. These tools can also strengthen defenses to help secure your computer against viruses and other security threats.
Microsoft Safety & Security Center
The Microsoft Safety & Security Center has information about Security scanners, tools, and safety guidelines for your computer, laptop, or mobile device. For more information, visit the following Microsoft webpage:
Security Troubleshooting and Support
The Security Troubleshooting and Support page has information about free tools that can help detect and remove viruses. The support page also contains information about how to strengthen defenses to help secure your computer against viruses and against other security threats. For more information, visit the following Microsoft webpage:
Microsoft security-related knowledge base articles
129972Computer viruses: description, prevention, and recovery
822158Virus scanning recommendations for Enterprise computers that are running currently supported versions of Windows
962007Virus alert about the Win32/Conficker worm
You receive a fraudulent e-mail message that claims that an attached executable is a Microsoft security update
What you can do to help prevent your computer from becoming infected
There is no method that can guarantee that your computer will be immune from malware. However, there are steps that you can take to lessen the risks. For more information, visit the following Microsoft webpage:
How to recognize phishing email messages, links, or telephone calls
Phishing email messages, websites, and telephone calls are designed to steal money. For more information about how to recognize these threats, visit the following Microsoft webpage:
Information about fake virus alerts and rogue security software
Rogue security software, also known as "scareware," is software that seems to be useful from a security perspective. However, this rogue security software provides limited or no security, generates incorrect or misleading alerts, or tries to lure users into participating in fraudulent transactions. For more information, visit the following Microsoft webpage:
How to get help if your Windows-based computer is infected with malware
If you want more help with a system that is infected by malware and you are currently located within the United States, you can obtain virus-related assistance from the Microsoft Answer Desk:
Answer DeskIf you are located outside the United States, visit the Microsoft Support Virus and Security Solution Center.